Can not get rid of voicemail notification (zero voicemail)

Hellow all I just got a ZenFone 2 (Android 5.0) and its great. It has one small problem I can not get the voicemail notification stating I have zero voice mails to go away. It alerts me every couple hours and the notification never goes away. I have gone into voicemail setting and turned the sound to "none" but still get a double default notification sound, again, rather randomly. Can anyone help?

Welcome to Android Central! See what happens if you wipe the cache partition, which won't erase any personal data: New Steps to Wipe Cache in Zenphone 2-ZE551ML. This process takes about 5-10 minutes on the ZenFone 2, so be patient.

Hellow all I just got a ZenFone 2 (Android 5.0) and its great. It has one small problem I can not get the voicemail notification stating I have zero voice mails to go away. It alerts me every couple hours and the notification never goes away. I have gone into voicemail setting and turned the sound to "none" but still get a double default notification sound, again, rather randomly. Can anyone help?

I tried it to no prevail. I still get a notification for 0 voicemails.